The portal protein of bacteriophage SPPl,.gp6, is a large homo-oligomer of 13 subunits. The connector (head/tail) is composed of the portal protein plus three other proteins. Masses are being determined for the portal protein alone, for a gp6tgp7 complex (the gp7 seems to bind in the hole af the portal), and for the whole connector complex, in order to determine the stoichiometry of the more minor proteins. The samples looked good, but the m analysis is not finished.